Flushing composition



, called sludge.

Patented a. 21, 1941 UNlT-ED STATES PATENT OFFICE rwsnme COMPOSITION Emile 1.. Baldeschwieler, Cranford, and 1mm 1).

Chew, Elizabeth, N. .L, assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application November 25, 1938, Serial No. 242,280

3 Claims.

The present invention relates to oily liquids that are used for lubricating and cleaning metallic surfaces, such as motor parts, and more particularly to a composition suitable for use as a solvent to re ove or flush sludge and other deposits from t e crankcases of automobile,'airplane and other types of motors and from machinery requiring lubrication at high temperatures.

It is well known that, in the normal course of internal combustion engine operation, some inlatter course, the solvent used has usually consisted of ordinary petroleum fractions or the more aromatic coal tar naphthas, either alone or in admixture with a light lubricating oil.

An .object of this invention is to provide an improved oily cleaning composition that will substantially dissolve the resinous and asphaltic material formed by the combination of oxygen with some ingredients of a lubricating oil while being used in an internal combustion motor.

Another object of this invention is to provide an improved oily cleaning composition of sufllciently high boiling range so that it will not evaporate to any appreciable extent when used for flushing a hot motor and at the same time will not be so high boiling thatit would facilitate decomposition when contacted with hot motor surfaces, such as the under-parts of the piston head, etc., in an automobile motor.

This and other objects and advantages will be obvious from the following description:

The general method used in cleaning ,internal combustion motors is to drain the used lubricating oil out of the crankcase, preferably while the motor is hot, addthe solvent oil, run the motor for several minutes and drain. This procedure usually must be repeated several times if it is desired to have the draining come out clear. The crankcase is then refilled with clean lubricating oil.

Flushing oils ordinarily used at the present time are light pale oil fractions of petroleum origin, not having suflicient body to be classed as good automotive lubricating oils, but having a suflicient body that when a small amount of such oil is left in an automobile crankcase, for example, after the flushing operation is completed, the resulting dilution of the fresh oil will not cause any harm during the operation of the motor.

Comparative tests are given below to illustrate the improved effectiveness of the flushing compositions prepared according to this invention over those used heretofore.

An automobile having a motor with 8 cylinders, 4 on each side set in the form of a V, with a mileage of 9304 recorded, was first inspected. In the pan, heavy sludge was found in the corners and on the bottom after the lubricating oil had been allowed to drain oif, the drain hole being set too high in the pan to completely empty the crankcase. In the upper part of the crankcase sludge was found in the comers-and on the pump shaft, slight sludge being present on the screen. 3 quarts of 9. treated paraflin oil having an A. P. I. gravity ofat least 28, flash of 365 F. A. S.

. T. M., and a Saybolt viscosity of 108 to 113 secquarts of the same flushing oil were added and onds at 100 F., were added and the automobile was driven for miles at normal driving speed. After the flushing oil was allowed to drain off, it was found that considerable sludgewas found on the bottom due to the height of the drain hole in the crankcase. The upper section of the crankcase was slightly improved and the efiectiveness of the flushing oil was consideredas In the crankcase of this same car, 5

the car was driven 367 miles. Upon draining this flushing oil, the pan and the upper section of the crankcase showed only a slight improvement in appearance over that obtained when the first flushing oil was used. The effectiveness was considered to be an additional 5%. The crankcase of the motor was then charged with a motor lubricating oil of 31 A. P. I. gravity, 63 seconds Saybolt viscosity at 210 F., and 32.5 seconds'saybolt' viscosity at F. and 425 F. flash. The car was then driven until the odometer, indicated a mileage of 11,433, and the oil was then drained and the pan and upper crankcase inspected. Sludge was found in the corners and on the bottom of the pan and also in the, corners and on the pump shaft of the upper crankcase. To this crankcase were then added 5 quarts of a flushing oil having a gravity of about 24.6. This flushing oil was'prepared by extracting a. lubricating oil with S02, separating the extract from the S02, washing with soda and then mixing with a Coastal pale oil. One-third of the S02 extract was mixed with two-thirds of the Coastal pale oil having a Saybolt viscosity of 500 seconds at 100 F. The mixture had Saybolt viscosities of 82.4 seconds at 100 F. and 36.9 seconds at 210 F. The automobile was driven for 300 miles, after which the crankcase was drained and inspected. A slight amount of sludge was found to be removed from the pan, and the upper part of the crankcase was found to be slightly improved although the sludge appeared to be somewhat softer. The efiectiveness was considered to be v A car of the same make with a mileage recording of 5971 was used for the following test: After the lubricating oil that had been used was removed, the pan was found to contain medium to heavy sludge in the corners, ends and on the bottom. The drain hole was also too high to remove all the liquid from the crankcase. In the upper part of the crankcase, sludge was found in the corners and on the pump shaft and engine parts. mixture of the S02 extract and the Coastal pale oil were added. After driving 77 miles, the crankcase was drained and it was found that considerable sludge had been removed from the corners. A thin sludge was found present on the bottom. Considerable sludge was removed from all engine parts. The effectiveness was considered as To this same automobile another charge of 5 quarts of the S02 extract and Coastal pale oil were added. The automobile was driven 1273 miles and the oil drained from the crankcase.

Into this crankcase, 5 quarts of a similar It was found that the pan contained very heavy A fi-cylinder car with an odometer reading of 36,369 was next used. The lubricating oil was drained from the crankcase and it was found that the pan contained sludge on the ends, and on the bottom and also some hard sludg'e was found in one spot on the bottom. The upper part of the crankcase contained heavy sludge in corners, slight sludge on throws and heavy sludge on the screen. The valve chamber also contained heavy sludge. To this crankcase were then added 4 quarts of the mixture of S02 extract oil and Coastal pale oil, together with 25% of acetone. After the motor was allowed to idle at a fast rate of speed for 15 minutes, the flushing material was allowed to drain.v The pan was found to be very little improved in appearance. In the upper part of the crankcase a small amount of sludge was found to be removed from the engine. The oil binder appeared partially broken. The valve chamber was substantially the same as before the flushing. The effectiveness was considered about 10%. The original oil was then returned to the crankcase together with some light lubricating motor oil and 10% of acetone. The automobile was then driven 50 miles. The crankcase was drained and the same conditions were found to be present as before. To. the same crankcase were then added 4 quarts of a flushing oil of about 28 A. P. I. gravity and a Saybolt viscosity of 108 to 113 seconds at 100 F., together with 10% of a-mixtureof equal parts of coal tar naphtha and kerosene. The engine was allowed to idle at a fast rate of speed for 20 minutes, after which the flushing oil was allowed to drain. The crankcase and engine parts were not improved by the removal of any sludge.

Another automobile having a G-cylinder motor with a mileage on the odometer of 14,645 was used in the next test. After draining the lubricating oil, light sludge was found present in the corners. There was hard sediment and road dirt on the bottom of the crankcase. The upper part of the crankcase contained heavy, solid-like sludge in the left corner, medium sludge in other corners, on oil lines and on crank throws. The oil screen was two-thirds plugged. To this crankcase 4 quarts of the treated paraffin oil having an A. P. I. gravity of at least 28, together with 25% of isopropyl alcohol, were added. The motor was allowed to idle at a fast rate of speed for 20 minutes, after which the flushing oil was drained. On inspection, it was found that a slight amount of sludge had been removed from the pan. From the upper part of the crankcase a slight amount of sludge was also removed. The binder appeared partially dissolved and the oil screen was not clean. The effectiveness was considered about 10%.

In this automobile was then set a tube drilled with very small holes set to direct spray at different angles and Varsol under pounds pressure was sprayed on the engine parts by inserting this tube through the pan oil drain hole of the crankcase. It was found that considerable amount of sludge was removed. The hard sludge at the bottom of the crankcase was loosened. From the upper part of the crankcase a major portion of the sludge was removed from the engine parts and oil filter. The effectiveness was considered to be 25 Another standard 6-cylinder automobile having an odometer showing 39,305 miles was used to determine the eifectiveness of various flushing oils. Upon draining the lubricating oil from the crankcase of the motor, light, soft sludge was found on the ends and hard sludge on one spot on the bottom. In the upper part of the crankcase, light and medium sludge was found present in the corners, traces of sludge on throws and the screen was two-thirds plugged with a mayonnaise-type of sludge. The valve chamber contained medium to heavy sludge. To this crankcase were then added 3 quarts of the: mineral flushing oil of at least 28 A. P. I. gravity, together with 14% of dichlorobenzene. The engine was allowed to idle at a high rate of speed for 20 minutes. Upon draining the flus ing oil, the pan on inspection disclosed that the sludge had been mostly removed from the 'ends and that the sludge on the bott0m was slightly attacked. From the upper part of the crankcase a slight amount of sludge had been removed. The screen was materially improved and the oil lines were apparently dissolved. The upper part of the crankcase was cleaned of most of the sludge from driven for 186 miles.

the engine parts and one-half of the sludge'was removed from the screen. The valve chamber was slightly cleaned; The effectiveness was considered about 50%.

Another automobile having 6 cylinders in the motor and an odometer reading of 56,002 was next used. On draining the lubricating oil, the pan was found to contain black, sticky sludge on 1 theends and in the corners. Hard sediment and a road dirt sludge were found on the bottom.

' some sludge remained in the corners and on the end. In the upper crankcase considerable amount of sludge was removed from the throws and-oil lines, although much sludge remained on' throws and in the corners. The valve chamber was unchanged. The effectiveness was considered about 30%. The same flushing oil was then returned to thecrankcase and the engine idled at a high rate of speed for 45 minutes while air was bubbled through the flushing composition by means of aconnection in the drain plug. On draining the oil, it was found that a'slight amount of sludge was removed from the corners;

' The loose sludge that dropped to the bottom of the pan from the upper part of the crankcase was .not washed away by draining. In the upper part of the crankcase somesludge remained in the corners and on the crank throws. However, the' binder appeared dissolved so that the sludge althe pan.

speed and" on draining the flushing composition, it was found that about 50% of the sludge was removed from the pan. 'In the upper part of the crankcase a small amount of sludge was removed from the throws. Considerable amount was removed from the lines. The sludge remining in the crankcase was dry and brittle in nature. The effectiveness was considered to be about 50%.

Another 6-cylinder automobile having an odometer record. of 34,339 miles was likewise used for the test. The pan on draining the lubricating oil was found to contain a medium amount of soft sludge on the ends. The upper part of the crankcase disclosed a medium amount of hard granular sludge adhering to all engine parts, together with some soft sludge. In the valve chamber was found a heavy deposit of soft sludge. To this crankcase were then added 3 quarts of a mixture of 75% of 28 A. .P. I. gravity flushing oil, 12 /2% of dichlorobenzene and 12 of isopropyl alcohol of 98 concentration. The engine was idled for 30 minutes at-a high rate of'speed. Upon draining the flushing oil, most of the sludge was found to be removed from Almost all of the'sludge was found to be removed from the engine parts and the upper part of the'crankcase. The hard granular sludge was slightly removed and the binder appeared dissolved. The valve chamber was slightly improved. The efi'ectiveness was considered about 50%.

Examination of the motors of the above automobiles after a period of normal operation folmost crumbled off and was easily removed by rubbing with a cloth. In the valve chamber, the amount of sludge was substantially the same but the stickiness much less. To this car was then added the regular amount of a well-known brand of motor lubricating oil. The automobile was At the'end of 186 miles the lubricating oil was removed. The pan was found to be, substantially 100% clean in the corners and on the ends, although some loose sludge was found that had dropped from the upper crankcase to the' bottom. The upper part of the cranklowing the flushing practices discussed above with these various agents revealed no corrosive effect. n Other chlorinated aromatic hydrocarbons, such as monochlorobenzene, dichlorobenzene, o, m or p monochlortoluene', monochlorpropylene, may be used from the motor. The chlorinated aromatic solvents having boiling points above 150 C. are preferred; Sludge dispersers were likewise found to aid the effectiveness of the flushing compositions. 4 The sludge dispersers preferred are voltolized fatty oils, such as rape'and sperm oils or a mixture of voltolized rape and mineral oil,

voltolized mineral oils such as petrolatum wax,

condensed compounds such as diphenyl oxide and chlorparafiin, together with naphthalene.

quantities of sludge dispersers used may be from the crankcase was made to determine if the sludge had been sufllciently loosened from the engine parts by the previous treatment so that I it may be removed by draining the oil. The results obtained'disclosed the efiectiveness of the process.

pump and on oil' lines. To the crankcase were then added 3 quarts of. a flushing oil of 20 A. P. I. gravity, 12 /2% of isoprcpyl alcohol of 98% con- --centration and 12 /2% of dichlorobenzene.-. The

motor was idled 15 minutes-at a high rate of the crankcase showed considerable sticky sludge on'throws, rear and side of the case above the 2 to 10%, although about 5% is preferred. From these tests it was determined that a flushing composition consisting of60 to of a mineral oil having a Saybolt viscosity of about 80 to 140 seconds at F. and a gravity of about 28"- A. P. 1., when blendedwith 5 to 20% of chlorinated aromatic solvent, such as dichlorobenzene, and 5 to 20% ofan aliphatic alcohol having not over 4 carbon" atoms to the molecule, preferably isopropyl alcohol, wasvery effective for removing the sludge deposits in automobile engines. The preferred formula of a flushing oil is one containing about 75% of lubricating oil 12%% of dichlorobenzene and 12 /z% of isopropyl alcohol of about 98% concentration. Larger proportions of dichlorobenzene may be used.

, This invention is not to belimited to the spe-- cific embodiments shown or the specific examples given, nor to any theories advanced as to the operation of the invention, but in the appended claims it is intended to claim all inherent noveltyin the invention as broadly as the prior art permits.

without suffering any. corrosion and effectively removing the sludges The We claim:

1. A flushing composition comprising 75% by volume of a mineral oil of not less than 28 A. P. I. gravity having a. Saybolt viscosity of 80 to 140 seconds at 100 F., 5% by volume of clichlorobenzene and by volume of isopropyl alcohol of 98% concentration.

2. A flushing composition comprising by volume of a mineral lubricating oil having a. Saybolt viscosity of to 140 seconds at F.,

12 92, by volume of dichlorobenzene and 12 by volume of isopropyl alcohol.

3. A flushing composition comprising 60 to 80% by volume of mineral oil of not less than 28 A. P. I. gravity having a Saybolt viscosity of 80 to seconds at 100 F., 5 to 20% by volume of dichlorobenzene and 5 to 20% by volume of isopropyl alcohol.

EMILE L. BALDESCHWIELER. ROBERT D. CHEW. 

